Peripheral devices, such as mobile wireless devices or personal data assistants, can be powered by internal means, such as an internal battery pack. The internal battery pack is an assembly of one or more batteries and provides a certain charge capacity. Different battery packs have different charge capacities, different termination voltages such as 4.2 V and 4.4 V, for example, as well as different charging/discharging characteristics. Typically, a battery pack has a battery ID resistor that indicates the battery type from which the charge capacity of the battery pack can be ascertained.
The charge capacity and the battery type are important for several reasons. For instance, if the battery is rechargeable, it is important to charge the battery to the proper charge capacity and at the proper rate. If the battery is overcharged, the battery and the mobile device in which it is used can both become damaged. This situation is becoming increasingly more likely due to the increased number of counterfeit batteries that are on the market. For battery packs with battery ID resistors, it is simple to read the resistance value of the battery ID resistor and manufacture a counterfeit battery pack with another resistor that has the same resistance value. However, the counterfeit batteries, as well as some third party non-authorized batteries, generally do not have the charge capacity of an authentic battery, may not have the required safety protection circuitry, and may not be compatible with the charging method being employed by the mobile device and therefore could possibly suffer catastrophic failure during charging, or through normal usage.
One way to deal with counterfeit battery packs may be to use “smart batteries” which include an embedded microprocessor that can be used to provide security capabilities.
In addition, the mobile wireless device usually maintains information for the different battery packs that can be used. For instance, the mobile wireless device can maintain information on the charging/discharging characteristics of various battery packs. This information may be in the form of a look-up table (LUT) that provides charge capacity versus voltage information. The information in the LUT can be used by the mobile wireless device to calculate and display battery charge capacity information to a user of the mobile wireless device. However, once a mobile wireless device is released into the market, it is difficult to maintain compatibility between the mobile wireless device and new batteries since the battery information stored on the mobile wireless device will be out of date for these new batteries. Each battery type has unique characteristics that are required knowledge for battery monitoring software. The battery monitoring software that ships with the mobile wireless device needs to be able to differentiate between different battery packs, so that the battery pack can be charged according to the maximum charge rate, as well as use battery curves that are specific to the type of battery pack. This is necessary so that the battery that ships with the device can be changed, and so that a user can change their battery in the future without incurring any problems. The data updating can be done through a software upgrade, but users find it inconvenient to update their mobile wireless device.
These and other features of the exemplary embodiments are described in more detail below.